Changed the changelog and documentation about

the select method (tag select) forces :include_blank  if is required and no multiple and
display size is one

actionpack/CHANGELOG.md

 ## Rails 4.0.0 (unreleased) ##
 
+*    The `select` method (select tag) forces :include_blank  if `required` is true and 
+    `display size` is one and `multiple` is not true. *Angelo Capilleri*
+
 *   `respond_to` and `respond_with` now raise ActionController::UnknownFormat instead
     of directly returning head 406. The exception is rescued and converted to 406
     in the exception handling middleware. *Steven Soroka*

guides/source/form_helpers.textile

@@ -405,6 +405,8 @@ Whenever Rails sees that the internal value of an option being generated matches
 
 TIP: The second argument to +options_for_select+ must be exactly equal to the desired internal value. In particular if the value is the integer 2 you cannot pass "2" to +options_for_select+ -- you must pass 2. Be aware of values extracted from the +params+ hash as they are all strings.
 
+WARNING: +:include_blank+ is forced true if the attributes +required+ is true, display +size+ is one and +multiple+ is not true.
+
 h4. Select Boxes for Dealing with Models
 
 In most cases form controls will be tied to a specific database model and as you might expect Rails provides helpers tailored for that purpose. Consistent with other form helpers, when dealing with models you drop the +_tag+ suffix from +select_tag+: